UWB Transmitter Chirp Pulse Modulation for Scalable Data Rates
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Solution Overview
Problem
Current ultra-wide band (UWB) systems face complexity and increased cost due to the need for adaptive filtering and sampling rate changes with varying data rates, requiring different filters and sampling rates at the UWB receiver and transmitter, which complicates the system and increases power consumption.
Innovation Solution
The implementation of a differential spreading encoder and DMPSK modulator in the UWB transmitter, along with a bit scrambler and phase detector, generates pulses with desirable cyclic autocorrelation properties, allowing for scalable data rates without changing the pulse on-off period, simplifying the system by using a single sampling rate and filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If adaptive filtering and sampling rate changes are implemented to handle varying data rates, then data rate adaptability is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent changes the fundamental parameter of pulse waveform from traditional short pulses to chirp pulses with linear frequency modulation. This parameter change enables the system to achieve different data rates by adjusting modulation schemes and coding rather than changing sampling rates or filters, thus maintaining data rate adaptability while reducing device complexity
Solution Approach 2:
The chirp pulse generator and DMPSK modulator are designed to handle multiple data rates using the same hardware components. The system achieves multi-functionality by using universal filtering and sampling mechanisms that work across different data rates, eliminating the need for multiple specialized filters and sampling rate converters
2Manufacturing precision
If different filters are used for different data rates, then signal quality is improved, but manufacturing complexity and cost increase
Solution Approach 1:
A single filter design is used that effectively processes signals across all data rates. The filter is optimized for the chirp pulse characteristics and works universally without needing to be changed or adjusted for different data rates, simplifying manufacturing while maintaining signal quality
Solution Approach 2:
Instead of changing filter parameters physically, the system maintains constant filter parameters while achieving different data rates through modulation and coding schemes. The chirp pulse's inherent time-frequency characteristics allow a fixed filter to effectively process varying data rates
3Productivity
If sampling rate changes are implemented for different data rates, then communication performance is improved, but power consumption increases
Solution Approach 1:
The system achieves variable data rates without changing the sampling rate by utilizing different modulation orders and coding rates on top of a fixed sampling framework. This eliminates the energy overhead of dynamic sampling rate adjustment while maintaining communication performance across different data rates
4Area of stationary object
If conventional short pulse UWB signals are used, then bandwidth coverage is improved, but autocorrelation properties and interference resistance deteriorate
Solution Approach 1:
The patent transforms the pulse waveform from conventional short pulses to chirp pulses with linear frequency modulation. This parameter change in waveform structure provides both wide bandwidth coverage and excellent autocorrelation properties, as the frequency sweep characteristic enables precise timing synchronization and interference rejection
Solution Approach 2:
The chirp pulse uses frequency modulation similar to vibration principles, where the frequency sweeps linearly across the bandwidth. This creates a signal with distinctive temporal and spectral characteristics that provide superior autocorrelation properties compared to simple short pulses
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a more adaptable and interference-resistant UWB system with reduced complexity, enabling efficient communication across different data rates while maintaining low power consumption.
Implementation Method 1
an UWB transmitter modulates an UWB signal including a chirp pulse or a 'series of short pulses' using a DMPSK modulation technique
Implementation Method 2
The chirp pulse is a frequency modulated carrier pulse where a modulating signal is a triangular waveform. The chirp pulse spans larger bandwidths (>= 500 MHz) and has excellent autocorrelation properties.
Implementation Method 3
The UWB receiver may mix and filter the incoming UWB signal to remove chirp signal from the incoming UWB signal.
Data Source
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AI summary
The present invention provides an ultra-wide band (UWB) system and method. In one embodiment, a transmitter of a low duty cycled ultra wide band (UWB) system includes a differential spreading encoder for encoding a phase of a bit sequence based on a reference bit sequence. The transmitter also includes a pulse generator for generating a number of pulses associated the bit sequence using the encoded phase of the bit sequence, where the number of pulses is equal to a length of the bit sequence. Moreover, the transmitter includes a DMPSK modulator for generating a modulated signal through modulating the number of pulses using a phase of a differential data symbol.